A simple and very fast function to check against CIDR.
Your previous examples are too complicated and involves a lot of functions call.
Here it is (only with arithmetic operators and call only to ip2long () and split() ):
<?php
function ipCIDRCheck ($IP, $CIDR) {
list ($net, $mask) = split ("/", $CIDR);
$ip_net = ip2long ($net);
$ip_mask = ~((1 << (32 - $mask)) - 1);
$ip_ip = ip2long ($IP);
$ip_ip_net = $ip_ip & $ip_mask;
return ($ip_ip_net == $ip_net);
}
?>
call example: <?php echo ipCheck ("192.168.1.23", "192.168.1.0/24"); ?>
Fonctions réseaux
Sommaire
- checkdnsrr — Résolution DNS d'une adresse IP
- closelog — Ferme la connexion à l'historique système
- dns_check_record — Alias de checkdnsrr
- dns_get_mx — Alias de getmxrr
- dns_get_record — Lit les données DNS associées à un hôte
- fsockopen — Ouvre un socket de connexion Internet ou Unix
- gethostbyaddr — Retourne le nom d'hôte correspondant à une IP
- gethostbyname — Retourne l'adresse IPv4 correspondant à un hôte
- gethostbynamel — Retourne la liste d'IPv4 correspondante à un hôte
- gethostname — Lit le nom de l'hôte
- getmxrr — Retourne les enregistrements MX d'un hôte
- getprotobyname — Retourne le numéro de protocole associé à un nom de protocole
- getprotobynumber — Retourne le nom de protocole associé à un numéro de protocole
- getservbyname — Retourne le numéro de port associé à un service Internet et un protocole
- getservbyport — Retourne le service Internet qui correspond au port et protocole
- header_register_callback — Enregistre une fonction de rappel pour l'envoi des en-têtes
- header_remove — Supprime un en-tête HTTP
- header — Envoie un en-tête HTTP brut
- headers_list — Retourne la liste des en-têtes de réponse du script courant
- headers_sent — Indique si les en-têtes HTTP ont déjà été envoyés
- http_response_code — Récupère ou définit le code de réponse HTTP
- inet_ntop — Convertit un paquet d'adresses internet en une représentation humainement lisible
- inet_pton — Convertit une adresse IP lisible en sa représentation in_addr
- ip2long — Convertit une chaîne contenant une adresse (IPv4) en notation décimale à point en une adresse entier long
- long2ip — Convertit une adresse entier long (IPv4) en sa notation décimale à point
- net_get_interfaces — Get network interfaces
- openlog — Ouvre la connexion à l'historique système
- pfsockopen — Ouvre un socket de connexion Internet ou Unix persistante
- setcookie — Envoie un cookie
- setrawcookie — Envoie un cookie sans encoder sa valeur en URL
- socket_get_status — Alias de stream_get_meta_data
- socket_set_blocking — Alias de stream_set_blocking
- socket_set_timeout — Alias de stream_set_timeout
- syslog — Génère un message dans l'historique système
add a note
User Contributed Notes 14 notes
claudiu at cnixs dot com ¶
17 years ago
Anton Avramov - lukav at lukav dot com ¶
7 years ago
An improved version of claudiu at cnixs dot com not using split and working with the following:
ip: 192.168.101.123, CIRD: 192.168.101.144/24
<?php
function ipCIDRCheck ($IP, $CIDR) {
list ($net, $mask) = explode ('/', $CIDR);
$ip_net = ip2long ($net);
$ip_mask = ~((1 << (32 - $mask)) - 1);
$ip_ip = ip2long ($IP);
return (($ip_ip & $ip_mask) == ($ip_net & $ip_mask));
}
?>
Anonymous ¶
8 years ago
improved version of philippe-at-cyberabuse.org's answer:
<?php
function cidrconv($net) {
$start = strtok($net,"/");
$n = 3 - substr_count($net, ".");
if ($n > 0)
{
for ($i = $n;$i > 0; $i--)
$start .= ".0";
}
$bits1 = str_pad(decbin(ip2long($start)), 32, "0", STR_PAD_LEFT);
$net = (1 << (32 - substr(strstr($net, "/"), 1))) - 1;
$bits2 = str_pad(decbin($net), 32, "0", STR_PAD_LEFT);
$final = "";
for ($i = 0; $i < 32; $i++)
{
if ($bits1[$i] == $bits2[$i]) $final .= $bits1[$i];
if ($bits1[$i] == 1 and $bits2[$i] == 0) $final .= $bits1[$i];
if ($bits1[$i] == 0 and $bits2[$i] == 1) $final .= $bits2[$i];
}
return array($start, long2ip(bindec($final)));
}
?>
David GASTALDIN ¶
17 years ago
Here a IP-Range to CIDRs function that I wrote for the purpose of filling my Postfix client.cidr with ripe-ncc data to block spamming from useless countries. Strcmp functions are meant to work around the silly PHP string comparison which inevitably tries compare strings as numbers when possible. I'll make no comment about that fact ... bit I have to bite my tong hard :
function PlageVersCIDRs($ip_min, $ip_max) {
$cidrs = array();
$ip_min_bin = sprintf('%032b', $ip_min);
$ip_max_bin = sprintf('%032b', $ip_max);
$ip_cour_bin = $ip_min_bin;
while (strcmp($ip_cour_bin, $ip_max_bin) <= 0) {
$lng_reseau = 32;
$ip_reseau_bin = $ip_cour_bin;
while (($ip_cour_bin[$lng_reseau - 1] == '0') && (strcmp(substr_replace($ip_reseau_bin, '1', $lng_reseau - 1, 1), $ip_max_bin) <= 0)) {
$ip_reseau_bin[$lng_reseau - 1] = '1';
$lng_reseau--;
}
$cidrs[] = long2ip(bindec($ip_cour_bin)).'/'.$lng_reseau;
$ip_cour_bin = sprintf('%032b', bindec($ip_reseau_bin) + 1);
}
return $cidrs;
}
philippe-at-cyberabuse.org ¶
22 years ago
PHP miss CIDR functions.
This one will convert a CIDR like this:
0.0.0.0/16 -> 0.0.0.0 - 0.0.255.255
127.0/16 -> 127.0.0.0 - 127.0.255.255
etc...
function cidrconv($net) {
$start=strtok($net,"/");
$n=3-substr_count($net, ".");
if ($n>0) { for ($i=$n;$i>0;$i--) $start.=".0"; }
$bits1=str_pad(decbin(ip2long($start)),32,"0","STR_PAD_LEFT");
$net=pow(2,(32-substr(strstr($net,"/"),1)))-1;
$bits2=str_pad(decbin($net),32,"0","STR_PAD_LEFT");
for ($i=0;$i<32;$i++) {
if ($bits1[$i]==$bits2[$i]) $final.=$bits1[$i];
if ($bits1[$i]==1 and $bits2[$i]==0) $final.=$bits1[$i];
if ($bits1[$i]==0 and $bits2[$i]==1) $final.=$bits2[$i];
}
return $start." - ".long2ip(bindec($final));
}
-dR ¶
9 years ago
This little function might come in handy
<?php
function cidr_range( $cidr, $chkip=null )
{
// Assign IP / mask
list($ip,$mask) = explode("/",$cidr);
// Sanitize IP
$ip1 = preg_replace( '_(\d+\.\d+\.\d+\.\d+).*$_', '$1', "$ip.0.0.0" );
// Calculate range
$ip2 = long2ip( ip2long( $ip1 ) - 1 + ( 1 << ( 32 - $mask) ) );
// are we cidr range cheking?
if ( $chkip != null && ! filter_var( $chkip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4) === false )
{
return ip2long( $ip1 ) <= ip2long( $chkip ) && ip2long( $ip2 ) >= ip2long( $chkip ) ? true : false;
} else {
return "$ip1 - $ip2";
}
}
var_dump( cidr_range( "127.0/16", "127.0.0.1" ) ); // bool(true)
var_dump( cidr_range( "127.0/16", "192.168.0.1" ) ); // bool(false)
var_dump( cidr_range( "192.168.0.0/24" ) ); // string(27) "192.168.0.0 - 192.168.0.255"
?>
nexxer at rogers dot com ¶
19 years ago
In Trevor Hemsley's translation of the perl range2cidr function, the
while ($end > $start)
condition should be
while ($end >= $start)
otherwise it won't work for /32s, ie if you feed range2cidr("1.2.3.4", "1.2.3.4").
-- nex
Anonymous ¶
21 years ago
Alternative cidr_conv function - a little easier to follow
function cidr_conv($cidr_address) {
$first = substr($cidr_address, 0, strpos($cidr_address, "/"));
$netmask = substr(strstr($cidr_address, "/"), 1);
$first_bin = str_pad(decbin(ip2long($first)), 32, "0", STR_PAD_LEFT);
$netmask_bin = str_pad(str_repeat("1", (integer)$netmask), 32, "0", STR_PAD_RIGHT);
for ($i = 0; $i < 32; $i++) {
if ($netmask_bin[$i] == "1")
$last_bin .= $first_bin[$i];
else
$last_bin .= "1";
}
$last = long2ip(bindec($last_bin));
return "$first - $last";
}
samuele at norsam dot org ¶
20 years ago
To find if an IP is in a net/mask (very fast):
<?php
function isIPIn($ip,$net,$mask) {
$lnet=ip2long($net);
$lip=ip2long($ip);
$binnet=str_pad( decbin($lnet),32,"0","STR_PAD_LEFT" );
$firstpart=substr($binnet,0,$mask);
$binip=str_pad( decbin($lip),32,"0","STR_PAD_LEFT" );
$firstip=substr($binip,0,$mask);
return(strcmp($firstpart,$firstip)==0);
}
?>
This function can be compacted, avoiding some variable settings, but the function will not be too clear to read...
Example code, used to made a kind of location service network-based:
<?php
$n = array ( "192.168.0.0/16" => "TUSCANY",
"192.168.1.0/24" => "- Florence",
"192.168.2.0/24" => "- Pisa",
"192.168.3.0/24" => "- Siena",
"192.168.64.0/21" => "- Tuscan Archipelago",
"192.168.64.0/23" => "--- Elba Island",
"192.168.66.0/24" => "--- Capraia Island",
"192.168.67.0/24" => "--- Giannutri Island");
// Normally you should use the following line
$myip = $HTTP_SERVER_VARS['REMOTE_ADDR'];
// This is first example: returns Tuscany/Pisa
$myip = "192.168.2.33";
// This is second example: returns Tuscany/T.Arch./Elba
$myip = "192.168.65.34";
echo "Your position:<br />\n";
foreach ( $n as $k=>$v ) {
list($net,$mask)=split("/",$k);
if (isIPIn($myip,$net,$mask)) {
echo $n[$k]."<br />\n"; }
}
?>
and so on...
dand at ddchosting.com ¶
18 years ago
When I was working on a project I ran into this problem with redirecting. My solution is as follows:
header("Refresh: 5; url=../main/main.php?".session_id()."");
This allowed me to pass the session_id() which is used throughout site to make sure user has loged in.
I hope this helps!
metator at netcabo dot pt ¶
19 years ago
Regarding samuele's note:
You can get faster code if you apply directly what happens in network devices, such as routers. If you AND (logic operation) the remote ip against the local netmask the result will be the network ip if the remote ip is from the local network. Example:
192.168.0.16 = 11000000.10101000.00000000.00010000
& 255.255.255.0 = 11111111.11111111.11111111.00000000
--------------------------------------------------------------
192.168.0.0 = 11000000.10101000.00000000.00000000
And now the code. My example uses a html form where you place the values you want to test:
<HTML><HEAD><TITLE>Check IP</TITLE>
</HEAD><BODY>
<form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="POST">
Hope you find this useful.
IP to check: <input type="text" name="ip"> <br>
Local network ip: <input type="text" name="net"> <br>
Local netmask: <input type="text" name="mask"> <br>
<input type="submit" name="check" value="Check it!">
</form>
<?php
/**
* @param string $ip IP to check in dotted decimal format
* @param string $net Network IP in dotted decimal format
* @param string $mask Netmask in dotted decimal format
* @returns true if the ip belongs to the network, false otherwise
**/
function isIPIn($ip, $net, $mask) {
//doesn't check for the return value of ip2long
$ip = ip2long($_POST['ip']);
$rede = ip2long($_POST['net']);
$mask = ip2long($_POST['mask']);
//AND
$res = $ip & $mask;
return ($res == $rede);
}
if (isset($_POST['check'])) {
echo isIPIn($_POST['ip'], $_POST['net'], $_POST['mask']) ? "IP IN.": "IP OUT.";
}
?>
</BODY><HTML>
anderson at piq dot com dot br ¶
21 years ago
If you want to get the interface of an IP, based on the local route table, use this.
function GetIfaceforIP($user_ip)
{
$route = "/bin/netstat -rn";
exec($route, $aoutput);
foreach($aoutput as $key => $line)
{
if($key > 1)
{
$line = ereg_replace("[[:space:]]+",",",$line);
list($network, $gateway, $mask, $flags, $mss, $window, $irtt, $iface) = explode(",", $line)
if((ip2long($user_ip) & ip2long($mask)) == ip2long($network))
{
return $iface;
}
}
}
}
trevor-hemsley at nospam dot dial dot pipex dot com ¶
22 years ago
Previous example of IP range to CIDR list does not cope with ranges as well as the perl Net::Netmask range2cidrlist() function. In PHP this looks like
<?
function imask($this)
{
// use base_convert not dechex because dechex is broken and returns 0x80000000 instead of 0xffffffff
return base_convert((pow(2,32) - pow(2, (32-$this)))), 10, 16);
}
function imaxblock($ibase, $tbit)
{
while ($tbit > 0)
{
$im = hexdec(imask($tbit-1));
$imand = $ibase & $im;
if ($imand != $ibase)
{
break;
}
$tbit--;
}
return $tbit;
}
function range2cidrlist($istart, $iend)
{
// this function returns an array of cidr lists that map the range given
$s = explode(".", $istart);
// PHP ip2long does not handle leading zeros on IP addresses! 172.016 comes back as 172.14, seems to be treated as octal!
$start = "";
$dot = "";
while (list($key,$val) = each($s))
{
$start = sprintf("%s%s%d",$start,$dot,$val);
$dot = ".";
}
$end = "";
$dot = "";
$e = explode(".",$iend);
while (list($key,$val) = each($e))
{
$end = sprintf("%s%s%d",$end,$dot,$val);
$dot = ".";
}
$start = ip2long($start);
$end = ip2long($end);
$result = array();
while ($end > $start)
{
$maxsize = imaxblock($start,32);
$x = log($end - $start + 1)/log(2);
$maxdiff = floor(32 - floor($x));
$ip = long2ip($start);
if ($maxsize < $maxdiff)
{
$maxsize = $maxdiff;
}
array_push($result,"$ip/$maxsize");
$start += pow(2, (32-$maxsize));
}
return $result;
}
?>
philippe-at-cyberabuse.org ¶
22 years ago
... and this one will do the opposite (o return NULL for invalid netblocks) :
1.0.0.0 1.0.255.255 -> 1.0.0.0/16
1.0.0.0 1.3.255.255 -> 1.0.0.0/14
192.168.0.0 192.168.0.255 -> 192.168.0.0/24
function ip2cidr($ip_start,$ip_end) {
if(long2ip(ip2long($ip_start))!=$ip_start or long2ip(ip2long($ip_end))!=$ip_end) return NULL;
$ipl_start=(int)ip2long($ip_start);
$ipl_end=(int)ip2long($ip_end);
if($ipl_start>0 && $ipl_end<0) $delta=($ipl_end+4294967296)-$ipl_start;
else $delta=$ipl_end-$ipl_start;
$netmask=str_pad(decbin($delta),32,"0","STR_PAD_LEFT");
if(ip2long($ip_start)==0 && substr_count($netmask,"1")==32) return "0.0.0.0/0";
if($delta<0 or ($delta>0 && $delta%2==0)) return NULL;
for($mask=0;$mask<32;$mask++) if($netmask[$mask]==1) break;
if(substr_count($netmask,"0")!=$mask) return NULL;
return "$ip_start/$mask";
}
